Steamed rice is a rice that has been subjected to steeping, thermal treatment, drying and, often, machining. This treatment permits, in particular, a non-sticky rice to be obtained, the grains of which are intact, but with the drawback that the cooking-time is lengthy. The invention overcomes this drawback by virtue of a steamed rice having a greatly shortened cooking-time.
The varieties of rice having an amylose content lower than 15%, relative to dry matter, include, in particular, perfumed varieties of rice from Thailand having an amylose content generally amounting to between 10% and 15%, which hitherto have been sold as they are, just blanched in order better to preserve all their aroma. There are many other, less expensive varieties of rice for steaming.
In accordance with the invention, steaming is carried out in respect of rice having an amylose content lower than 15% by weight, relative to dry matter, amounting in particular to between 10% and 15%.
It has been found, unexpectedly, that steamed rice having an amylose content lower than 15% by weight, relative to dry matter, whether it be cargo rice or paddy rice, can be cooked in 5 minutes after being subjected to steaming. Varieties of rice having an amylose content lower than 10% are known which are also suitable for the invention.
Steamed rice that is suitable for rapid cooking can preferably be prepared by steeping the rice having an amylose content lower than 15% by weight in water at a temperature lower than 70xc2x0 C., in particular between 40 and 70xc2x0 C., under such conditions and for such a time that, after removal of the surface water by drainage or spin-drying, steeped rice is obtained having a moisture content by weight greater than 31%, by afterwards carrying out a gelatinisation of the steeped rice by heating it to a temperature greater than 130xc2x0 C. while maintaining the moisture at a weight content greater than 22% for a sufficient period, for example a period of at least 8 minutes, to obtain core-gelatinised rice, and by carrying out gelatinisation by causing the steeped rice to pass continuously into an enclosure so as to limit, by virtue of the equilibrium which is established within the enclosure between the moisture content of the rice which is undergoing gelatinisation and the moisture content of the gaseous atmosphere of the enclosure, the quantity of vapour emitted from the rice during gelatinisation, in order to maintain the moisture content by weight of the rice in the course of gelatinisation at a value greater than 22%, and by heating up the steeped rice in the enclosure essentially by conduction so as not to increase the moisture content by weight of the gelatinised rice appreciably, and in particular so as not to exceed a content of 28%.
When carrying out a standard parboiling in water vapour it is found that this type of rice cooks more rapidly than the other types.
The grains of parboiled rice have the following property: the cooked grains, placed in a hermetically sealed receptacle and put in the refrigerator at 4xc2x0 C. for 6 days, have a firmness measured in the visco-elastograph equal to or less than 120% of that which they have 15 minutes after cooking. This property is very much sought-after, particularly when a dish has to be prepared in advance. The grains do not harden upon cooling.